terraform-apply

terraform-apply action

This is one of a suite of terraform related actions - find them at dflook/terraform-github-actions.

This action applies a terraform plan. The default behaviour is to apply the plan that has been added to a PR using the terraform-plan action.

If the plan is not found or has changed, then the apply action will fail. This is to ensure that the action only applies changes that have been reviewed by a human.

You can instead set auto_approve: true which will generate a plan and apply it immediately, without looking for a plan attached to a PR.

Demo

This a demo of the process for apply a terraform change using the dflook/terraform-plan and dflook/terraform-apply actions.

GitHub

To make best use of this action, require that the plan is always reviewed before merging the PR to approve. You can enforce this in github by going to the branch settings for the repo and enable protection for the master branch:

1. Enable 'Require pull request reviews before merging'
2. Check 'Dismiss stale pull request approvals when new commits are pushed'
3. Enable 'Require status checks to pass before merging', and select the job that runs the plan.
4. Enable 'Require branches to be up to date before merging'

Inputs

These input values must be the same as any terraform-plan for the same configuration. (unless auto_approve: true)

• path

  Path to the terraform configuration to apply

  • Type: string
  • Required

• workspace

  Terraform workspace to run the apply in

  • Type: string
  • Optional
  • Default: default

• label

  An friendly name for the environment the terraform configuration is for. This will be used in the PR comment for easy identification.

  It must be the same as the label used in the corresponding terraform-plan command.

  • Type: string
  • Optional

• variables

  Variables to set for the terraform plan. This should be valid terraform syntax - like a variable definition file.

  with:
    variables: |
      image_id = "${{ secrets.AMI_ID }}"
      availability_zone_names = [
        "us-east-1a",
        "us-west-1c",
      ]

  Variables set here override any given in var_files.

  • Type: string
  • Optional

• var

  ⚠️ Deprecated: Use the variables input instead.

  Comma separated list of terraform vars to set.

  This is deprecated due to the following limitations:

  • Only primitive types can be set with var - number, bool and string.
  • String values may not contain a comma.
  • Values set with var will be overridden by values contained in var_files

  You can change from var to variables by putting each variable on a separate line and ensuring each string value is quoted.

  For example:

  with:
    var: instance_type=m5.xlarge,nat_type=instance

  Becomes:

  with:
    variables: |
      instance_type="m5.xlarge"
      nat_type="instance"

  • Type: string
  • Optional

• var_file

  Comma separated list of tfvars files to use. Paths should be relative to the GitHub Actions workspace

  • Type: string
  • Optional

• backend_config

  Comma separated list of terraform backend config values.

  • Type: string
  • Optional

• backend_config_file

  Comma separated list of terraform backend config files to use. Paths should be relative to the GitHub Actions workspace

  • Type: string
  • Optional

• parallelism

  Limit the number of concurrent operations

  • Type: number
  • Optional
  • Default: 10

• target

  Comma separated list of targets to apply against, e.g. kubernetes_secret.tls_cert_public,kubernetes_secret.tls_cert_private

  This only takes effect if auto_approve is also set to true.

  • Type: string
  • Optional

• auto_approve

  When set to true, generated plans are always applied.

  The default is false, which requires plans to have been approved through a pull request.

  • Type: bool
  • Optional
  • Default: false

Environment Variables

• GITHUB_TOKEN

  The GitHub authorization token to use to fetch an approved plan from a PR. The token provided by GitHub Actions can be used - it can be passed by using the ${{ secrets.GITHUB_TOKEN }} expression, e.g.

  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

  • Type: string
  • Optional

• TERRAFORM_CLOUD_TOKENS

  API tokens for terraform cloud hosts, of the form <host>=<token>. Multiple tokens may be specified, one per line. These tokens may be used with the remote backend and for fetching required modules from the registry.

  e.g for terraform cloud:

  env:
    TERRAFORM_CLOUD_TOKENS: app.terraform.io=${{ secrets.TF_CLOUD_TOKEN }}

  With Terraform Enterprise or other registries:

  env:
    TERRAFORM_CLOUD_TOKENS: |
      app.terraform.io=${{ secrets.TF_CLOUD_TOKEN }}
      terraform.example.com=${{ secrets.TF_REGISTRY_TOKEN }}

  • Type: string
  • Optional

• TERRAFORM_SSH_KEY

  A SSH private key that terraform will use to fetch git module sources.

  This should be in PEM format.

  For example:

  env:
    TERRAFORM_SSH_KEY: ${{ secrets.TERRAFORM_SSH_KEY }}

  • Type: string
  • Optional

Outputs

An action output will be created for each output of the terraform configuration.

For example, with the terraform config:

output "service_hostname" {
  value = "example.com"
}

Running this action will produce a service_hostname output with the same value. See terraform-output for details.

Example usage

Apply PR approved plans

This example workflow runs for every push to master. If the commit came from a PR that has been merged, applies the plan from the PR.

name: Apply

on:
  push:
    branches:
      - master

jobs:
  apply:
    runs-on: ubuntu-latest
    name: Apply approved plan
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: terraform apply
        uses: dflook/terraform-apply@v1
        with:
          path: my-terraform-config

Always apply changes

This example workflow runs for every push to master. Changes are planned and applied.

name: Apply

on:
  push:
    branches:
      - master

jobs:
  apply:
    runs-on: ubuntu-latest
    name: Apply terraform
    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: terraform apply
        uses: dflook/terraform-apply@v1
        with:
          path: my-terraform-config
          auto_approve: true

Apply specific resources

This example workflow runs every morning and updates a TLS certificate if necessary.

name: Rotate certs

on:
  schedule:
    - cron:  "0 8 * * *"

jobs:
  apply:
    runs-on: ubuntu-latest
    name: Rotate certs
    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: terraform apply
        uses: dflook/terraform-apply@v1
        with:
          path: my-terraform-config
          auto_approve: true
          target: kubernetes_secret.tls_cert_public,kubernetes_secret.tls_cert_private

Applying a plan using a comment

This workflow applies a plan on demand, triggered by someone commenting terraform apply on the PR. The plan is taken from an existing comment generated by the dflook/terraform-plan action.

name: Terraform Apply

on: [issue_comment]

jobs:
  apply:
    if: github.event.issue.pull_request && contains(github.event.comment.body, 'terraform apply')
    runs-on: ubuntu-latest
    name: Apply terraform plan
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: Checkout
        uses: actions/checkout@v2
        with:
          ref: refs/pull/${{ github.event.issue.number }}/merge

      - name: terraform apply
        uses: dflook/terraform-apply@v1
        with:
          path: my-terraform-config